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8. 9. 2021.
LFU violations in leptonic τ decays and B-physics anomalies
We present a complete analysis of Lepton Flavor Universality (LFU) violations in leptonic τ decays in motivated models addressing the B-physics anomalies, based on the SU(4)×SU(3)×SU(2)×U(1) gauge group. We show that the inclusion of vector-like fermions, required by B-physics data, leads to sizable modifications of the leading-log results derived within an Effective Field Theory approach. In the motivated parameter-space region relevant to the B-physics anomalies, the models predict a few per-mil decrease of the effective W -boson coupling to τ , within the reach of future experiments.